Things to do on the plot April

Written by Behemoth

Let a spot of warmer weather and the not-so-occasional shower to water in your new plantings tempt you outdoors, with Behemoth's guide to April tasks on the plot.

April is a busy month. We’re past the Equinox, there’s more daylight, the days are getting longer and things are (hopefully) warming up. This means the sowing season gets underway outside and earlier sowings made undercover can be planted out. The weeds will also start to make their presence felt.

General Tasks

Sharpen your hoe!

Look at your diary and book yourself the time to make the sowings. Don’t put it off.

Outdoor Sowings

Potatoes

If the weather in March has continued to be too cold, get potatoes in the ground as soon as you can in April. Plant with the chits upward. Either dig a trench, or a set a line and dig a hole for each spud 12cm (5”) deep. Space first and second earlies 30cm (1ft) apart, main crop 37cm (15”) apart, with 60-75cm (24-30”) between rows. You can now take part in the great “Earth Up, or Not Bother?” debate. You may wish to give shoots a covering of fleece or newspaper on cold nights but I’ve never bothered.

Beetroot

2cm (1”) deep, in rows 30cm (1ft) apart.

Carrots

1cm (.5”) deep, in rows 30cm (1ft) apart.

Salsify

1cm (.5”) deep, in rows 30cm (1ft) apart – in later April

Scorzonera

1cm (.5”) deep, in rows 30cm (1ft) apart – in later April

Parsnips

1cm (.5”) deep, in rows 30cm (1ft) apart. Parsnips can take a long time to germinate - up to three weeks - so mark the row well. One tip is to sow some radishes alongside, as these will germinate sooner and mark the row when you are weeding, as well as giving you a quick catch crop.

These will need thinning later on so don’t sow too thickly and waste seed. I’ve found it easy to sow three seeds at the recommended final intervals and to thin if necessary.

Broad Beans

Sow in pairs about 20cm (8”) apart in a 5cm (2”) deep trench scraped out with a hoe. The plants will support each other. Space rows at 45cm (18”) apart.

Kohl Rabi

1cm (0.5”) deep in rows 30cm (1ft) apart. Cover the row with fleece or garden mesh after sowing. This will protect the seedlings fro flea beetle which can shred the leaves.

Radishes, Lettuces, Spring Onions

Sow these 1cm (0.5”) deep in short rows about 30cm (1ft) apart to prevent a glut. Cover the row of radishes with fleece or garden mesh after sowing. This will protect the seedlings from flea beetle which can shred the leaves. You can plant out any sowings made under cover last month but they may still need some protection.

Onions from Seed

Sow 1cm (0.5”) deep in rows 30cm (1ft) apart. Onions sown in pots in March need transplanting to individual-cell trays or modules to plant out in May.

Onion sets

10cm (4”) apart in rows 30cm (1ft) apart. These should have been heat-treated to stop them bolting

Shallots

Weather permitting, finish planting them in April. You should allow 18cm (7”) between shallots in rows 30cm (1ft) apart.

Hardy herbs

These can now be started in a seed bed, 1cm (0.5”) deep, in rows about 15cm (6”) apart. A seed bed is an area of soil that has been dug over and then raked level to a level, smooth consistency. The idea is that the seeds are sown in the seed bed and thinned as necessary until they are large enough to be transplanted to their final growing position.

However, seed beds can be prone to slug attack, flea beetle, erratic germination and drying out among other things. I’ve had more success sowing individually into 7.5cm (3”) pots or root trainers filled with moist compost. Barely cover the seed with a layer of compost. Germination is more consistent and there is less wastage of seed. These pots do not need to be under cover and are probably best on a bench somewhere. As the shoots grow you’ll need to net them to stop the birds having a go.

When the plants are of a good size with a decent root ball they can be transplanted to their final growing positions. Plants started off undercover in February and March and hardened off can be planted out now. Net them!

Herbs

In late April you can sow rosemary, thyme, marjoram, chives, garlic chives, fennel and dill direct. Broadcast sow and then cover with 1cm (0.5”) of soil.

Green Manure

Don’t let the weeds get hold. Cover fallow areas with a permeable weed suppressant fabric or other similar material such as cardboard, layers of newspaper or old carpet reserved for this task.

In the cold frame

This is the time of year when a simple cold frame comes into its own. Small green houses, cloches and mini poly tunnels serve a similar purpose. Ideally, you need to know roughly when your last frost usually occurs. Down South this can be as early as mid April in the Midlands and Northern England mid to late May. Further North it may be late May. About a month before the last frost you can sow tender plants in pots (usually 7.5cm/3”) or root trainers and put them in the cold frame. This will give them an early head start. As with any plant that is started under cover they will appreciate being ‘hardened off’ before going outside. This means opening the cold frame and exposing them to the general weather conditions as the get bigger but still protecting them at night.

Runner Beans

Sweetcorn

Sunflowers

Tomatoes

(NB - these will be affected by low night-time temperatures and may struggle)

Courgettes

Set seed on its edge and cover with its own depth of compost, in a 12cm (5”) pot

Marrows

Set seed on its edge and cover with its own depth of compost, in a 12cm (5”) pot

Pumpkins and Squashes

Maybe a little bit early for northern gardeners but worth a go - set seed on its edge and cover with its own depth of compost, in a 12cm (5”) pot

Globe artichokes

1cm (0.5”) deep

Cardoons

1cm (0.5”) deep

Lettuce

In trays or pots.

Such early sowings will be sensitive to the vagaries of the weather and may not be successful until late in the month or even May. Of course any of the above can be done in the greenhouse or polytunnel as well.

Under cover

Tomatoes

You can still sow tomatoes now for a later crop or undercover for a crop destined to go outside. Alternatively, buy in plants from garden centres or other sources. Young plants from earlier sowings can be planted in their growing position when night-time temps stay above 10C (50F) – this is usually late April or early May. To get them off to a good start make sure their planting position is well watered in advance. Ideally dig a hole and fill it with water several times so the subsoil gets a good soak. Fill the hole with compost and put the support cane in place now.

Cucumbers

Can be sown well into May. Cucumbers don’t like low temperatures and may require a bit more attention than most crops. They should not be in an unheated structure overnight until well into May and don’t over water them to avoid root rot.

Plants sown in March can go into their growing positions by the end of April but be prepared to help them with some fleece if its frosty outside.

French beans

Can be sown direct in the border, or in pots if you choose.

Sweetcorn, pumpkins and squash

Can be started as above for the cold frame.

Keep managing the crops you planted in the autumn and early spring. Clear any raggy specimens or exhausted crops out of the way ready for the pot sowings to come.

Temperatures can vary enormously a this time of year so attempt to keep the tunnel or greenhouse ventilated and at a steady 20-25C (68-77F). Also be ensure that growing plants are correctly watered.

Fruit

Control weeds now. Dig out perennial weeds and hoe out any weed seedlings. However, do this with care and consideration as you don’t want to disturb shallow-rooted fruit such as raspberries and strawberries. A good weed around the raspberries now and a heavy mulch of compost, manure or bark chippings will do a lot to suppress weeds during the spring and summer.